Factors contributing to time to diagnosis in symptomatic colorectal cancer: A scoping review

Colorectal cancer (CRC) is the third most common cancer worldwide (Ferlay et al., 2015, International Journal of Cancer, 136, E359), and delayed diagnosis is associated with mortality (Tørring et al., 2011, British Journal of Cancer, 104, 934; Tørring et al., 2012, Journal of Clinical Epidemiology, 65, 669). The purpose of this review was to determine the factors associated with time to diagnosis in symptomatic CRC using scoping review methods.

We performed database and citation searches to identify studies which examine the length of any interval from symptom presentation to diagnosis. Study selection was conducted by two independent reviewers. Factors contributing to time to diagnosis were extracted from selected articles and mapped onto a conceptual framework consisting of four levels: patient and disease factors, provider factors, organisation/setting factors and sectors of influence.

From the 31 studies included in this review, we identified 138 unique factors, 17 of which were investigated by at least three studies and 11 of which had consistent results. Patient and disease factors were most commonly studied. Patient perception that their symptoms were benign, a non-urgent referral, female sex and rectal tumour location were each associated with a longer time to diagnosis.

Thus far, the literature has focused on patient or disease-related factors, while other levels of influence have been relatively understudied.